The principal objective of the proposed research is to study interactions between motivational and cognitive processes in choice behavior. It has been shown that predictions, bets, and other decisions concerning uncertain events are affected not only by available information about the likelihood of the events and by the values that depend upon the correctness of the decisions, but also by independent outcome-values, i.e., values that depend only upon the occurrence or nonoccurrence of the events and not upon the decisions themselves. The effects of independent outcome-values are "irrational" by most criteria and give the appearance of an interaction between "utility" and "subjective probability" that violates most current theories of decision-making. This research attempts to discover the conditions under which these effects show themselves and to determine whether they constitute a fundamental interaction between cognitive and motivational processes or whether they can be ascribed to strategies and hypotheses employed, sometimes mistakenly, by the subjects.